Content-centric networking, which focuses on access to contents regardless of the original hosts (of the contents), provides an ideal communication service for content distribution, sharing, and retrieval in large-scale distributed systems. See for example, A. Carzaniga et al., “Forwarding in a content-based network,” ACM SIGCOMM (2003), A. Carzaniga et al., “A routing scheme for content-based networking,” ACM INFOCOM (2004) and V. Jacobson et al., “Networking named content,” ACM CoNEXT (2009). Unlike traditional host-oriented networking, with content-centric networking any node that has a copy of the requested data can respond to the requester, thus reducing access latency, network congestion, and bandwidth consumption. The performance of a content-centric network will depend on several factors. One of the important factors is the availability of content replicas near nodes that might request the content. Thus it is important to design a good mechanism to ensure popular contents are strategically replicated and placed near every node. In a highly dynamic network environment, such as mobile ad hoc networks (MANETs) and wireless peer-to-peer networks, the strategic replica placement is a very challenging task due to the constant changes of network topologies.
Existing replication techniques have been mainly designed for stationary networks, thus they will not be suitable for content placement and management in a dynamic MANET due to prohibitively high management overhead. See, for example, I. Baev et al., “Approximation algorithms for data placement in arbitrary networks,” SODA (2001) (hereinafter “Baev”), E. Cohen et al., “Replication strategies in unstructured peer-to-peer networks,” ACM SIGCOMM (2002), T. Hara et al., “Effective replica allocation in ad hoc networks for improving data accessibility,” IEEE INFOCOM (2001), Ko et al., “Distributed, self-stabilizing placement of replicated resources in emerging networks,” IEEE ICNP (2003) (hereinafter “Ko”), L. Qiu et al., “On the placement of web server replicas,” IEEE INFOCOM (2001) (hereinafter “Qiu”) and B. Tang et al., “Benefit-based data caching in ad hoc networks,” IEEE INFOCOM (2006) (hereinafter “Tang”). The current opportunistic caching mechanisms do not try to optimize content placement based on a well-defined performance objective. Hence, they may not result in good performance.
Therefore improved techniques for managing content in a dynamic MANET would be desirable.